Prevention of occupational hand eczema in healthcare workers during the COVID‐19 pandemic: A controlled intervention study

Abstract Background Occupational hand eczema (HE) is common among healthcare workers (HCWs) and has—in some regions of the world—increased during the COVID‐19 pandemic due to related hygiene measures. Objectives To evaluate the efficacy of an intervention for HE prevention in HCWs during the pandemic. Methods A prospective, controlled, unblinded interventional trial was conducted in 302 HCWs. The intervention group (IG) (n = 135) received online‐based health education and free access to hand cleansing and hand care products. The control group (CG) (n = 167) did not receive any intervention within the study. At baseline (T0), after 3 (T1) and 6 (T2) months, participants completed standardized questionnaires. The Osnabrueck Hand Eczema Severity Index (OHSI) was assessed at T0 and T2. Results During the observation period, there were no new HE cases in the IG (n = 115) and 12 cases (8.8%) in the CG (n = 136). OHSI values at T2 were lower in the IG (b = −1.44, p < 0.001). Daily use of emollients was higher at work (b = 1.73, p < 0.001) and at home (b = 1.62, p < 0.001) in the IG at T2. Conclusions The intervention was effective in HE prevention and improving skin care behaviour during the COVID‐19 pandemic.


| INTRODUCTION
Healthcare workers (HCWs) are exposed to a considerable amount of wet work 1 and thus, at high risk of developing hand eczema (HE), mainly caused by irritant contact dermatitis. 2 A 1-year prevalence of HE in HCWs of around 20% has been reported previously. 2 Occupational HE is often chronic, burdensome and associated with impaired quality of life. [3][4][5] In some cases, it may even result in leaving the workforce. Consequently, the health economic burden is high due to direct (e.g., medical treatment costs) and indirect costs (e.g., costs for sickness-related work absences). 6,7 Intensified hand hygiene measures have been implemented for containing the coronavirus disease 2019 (COVID-19) pandemic 8 which emerged in the beginning of 2020 and has led to increased skin strain in the general population and particularly in HCWs who face a double burden due to elevated hygiene measures both in private life and at work. 9,10 Accordingly, recent studies from different countries have demonstrated that prevalence of occupational dermatoses in HCWs has increased during the COVID-19 pandemic. [11][12][13] In our study period, more than 100 000 occupational COVID- 19 infections in HCWs were reported in Germany leading to further tightening of hygiene measures and an unprecedentedly high incidence of contact dermatitis.
In several intervention studies, it has been shown that health education is effective in the prevention of occupational hand eczema. [14][15][16] Recommendations for preventing occupational HE include the use of adequate skin cleansing substances and skin care products, 17

| Participants
HCWs from 35 wards were recruited in two hospitals in Osnabrück and in Bad Rothenfelde which are located 30 km away from each other in Lower Saxony, Germany. After gaining permission from the hospitals' hygiene managements, nursing directorates, staff councils, medical directorates and company health managements, volunteers of one hospital (Osnabrück) were allocated to the intervention group (IG) and volunteers of the other hospital (Bad Rothenfelde) were allocated to the control group (CG). No further randomization within hospitals was done to avoid cross-contamination among the participants in terms of knowledge and study products. The inclusion criteria were written informed consent, being of legal age and working in healthcare (e.g., nurses, surgical assistants, physiotherapists). HCWs with known allergies against fragrances and/or oat flour could not participate in the IG due to the composition of the provided study products. Termination criteria were adverse skin reactions from the study products (only IG) or discontinuation of working in healthcare.

| Intervention group
The two-part intervention comprised free access to a lipid-containing syndet and an emollient for use both at work and at home accompanied by free access to an online training course on the prevention of hand eczema consisting of an e-learning video of 35-min length. An asynchronous store-and-forward technology was chosen to enable flexible access to the educational intervention and to avoid face-toface education during the COVID-19 pandemic. Schedule planning for the online-based health education with the indicative target 'Participants implement a considerate and careful skin cleansing and skin care behaviour within their private and occupational surroundings' is provided in Table S1.
After recruitment and baseline data collection, participants received a handout with the key information about the online-based health education which included a link and a quick response (QR) code with which the video could be retrieved. Furthermore, participants were provided with an information leaflet about HE, including a link list with additional helpful short videos about skin cleansing and skin care (Appendix S2), and additional information sheets about the appropriate use of protective gloves and adequate skin care behaviour. Participants initially received a starter kit containing four packages of the lipid-containing syndet and four packages of the emollient. Further packages could be demanded by the participants without limitation over the whole observation period. The ingredients of the study products are listed in Table S2.

| Control group
The CG did initially not receive an intervention within the study. No changes were made to the access to skin products provided by the hospital (treatment as usual). After the study was completed, the CG received access to the online-based health education and was provided with one package each of the lipid-containing syndet and the emollient.

| Outcomes and assessment instruments
The primary outcome was presence/absence of HE, which was primarily assessed by using the validated Osnabrueck Hand Eczema Severity Index (OHSI) [18][19][20] at T0 (baseline) and T2 (after 6 months). All skin examinations in the CG were conducted by a dermatologist experienced in occupational skin diseases (S.M.J.). The same dermatologist performed the (unblinded) skin examination in the IG, partially assisted by two other experienced occupational dermatologists. HE was defined as the presence of (i) vesicles or (ii) erythema score >2 in combination with a score >2 for at least one of the following clinical signs on the hands (papules, scaling, fissures) based on the OHSI assessment (modified from Reich et al. 21 ). The primary outcome was additionally assessed by using a paper-based questionnaire, including the question: 'Do you currently suffer from hand eczema' as well as additional questions about atopy ('Have you ever had an itchy rash that has been coming and going for at least 6 months, and at some time has affected skin creases?'), which was designed in consideration of the Nordic Occupational Skin Questionnaire (NOSQ-2002) 22 and distributed at T0, T1 (after 3 months) and T2. Individual HE signs assessed by the OHSI and the overall OHSI score were considered in terms of a secondary outcome. Other secondary outcomes were skin care behaviour (i.e., frequency of emollient use at work and at home) which were assessed by using the aforementioned questionnaire at T0, T1 and T2.

| Statistical methods
Data were analysed in the sense of an intention-to-treat analysis.
Multiple imputation (30 imputations) was conducted by applying fully conditional specification 23 to counterbalance missing data. In terms of descriptive statistics, frequencies and percentages were calculated for categorical variables and mean ± standard deviation (SD) for continuous variables using IBM SPSS Statistics (version 26).
Inferential analyses were performed using R (version 4.0.2). The level of significance was p < 0.05. With respect to the primary and secondary outcomes, linear or logistic multilevel modelling (MLM) was used (Tables S3 and S4). Full R code and output is available at osf (https:// osf.io/tyshu/?view_only=dca9217a95d743b1ac8c2cc3fcacda6c).
For examining factors possibly related to developing HE in the CG, logistic regression was conducted by using OHSI-based assessment F I G U R E 1 Consolidated Standards of Reporting Trials (CONSORT) 2010 flow diagram for T0 (baseline), T1 (after 3 months; 1st follow-up) and T2 (after 6 months; 2nd follow-up); multiple imputation (30 imputations) was conducted by applying fully conditional specification to counterbalance missing data T A B L E 1 Baseline demographic and clinical characteristics of the participants in the intervention group (IG), the control group (CG) and overall IG (n = 135) CG (n = 167) All (n = 302) Cigarettes/day, mean ± SD 11.6 ± 6.5 14.0 ± 5.0 11.9 ± 7.0 Abbreviations: CG, control group; IG, intervention group; SD, standard deviation. a The n mentioned in the preceding line has to be considered for calculating the percentage in this line. data at T2 as dependent variable, and several baseline variables (e.g., atopy) as predictors.

| Recruitment
Recruitment started on 1 December 2020 and was finished on 29 January 2021. This recruitment interval was necessary due to organizational reasons (e.g., work schedules, holidays etc.). A total of 302 HCWs were included in this study. Follow-ups were done in 3-month intervals between T0 and T1 as well as T1 and T2 (i.e., 6-month observation period overall for each participant).

| Participant flow
The

| Baseline data
The demographic and clinical characteristics of the participants were similar in both groups (

| Drop-out analysis
According to dropout analysis (

| Utilization of the intervention concept by participants
A total of 1800 lipid-containing syndets and 1800 emollients were distributed to the 135 participants of the IG during the study period.
The online training course was accessed by 66.6% of the participants of the IG. based on the dermatologically assessed data, which was slightly larger than the estimate of 4.6% based on self-reported data ( Table 2). Selfreported data on HE did merely correlate in a moderate way with the dermatologically assessed data (r = 0.31).

| Factors associated with hand eczema
Logistic regression predicting HE (OHSI-based assessment) at T2 in the control group revealed that only an atopic skin diathesis (i.e., itchy rash with skin creases affected) seems to be a relevant predicting factor for higher odds of developing HE (Table 3).  were also found. However, the magnitude was smaller. The respective results are displayed in Figure S1.

| Skin care behaviour
Results on the self-reported daily frequency of emollient use at work and at home are presented in Figure 3. At T0, both groups provided equal or nearly equal values. Regarding self-reported daily frequency of emollient use at work, there was a statistically significant difference between IG and CG at T2 with higher frequency in the IG than in the CG (b = 1.73, p < 0.001) and a statistically significant difference between IG and CG with respect to improvement within the observation period with stronger improvement of the values in the IG com-

| DISCUSSION
With this interventional trial in HCWs, we were able to show that a two-part intervention consisting of free access to an adequate hand cleansing product and emollient accompanied by free access to an online-based health education was effective not only in the prevention of incident hand eczema but also in improving the skin condition of the hands. A strength of this study is that regardless of the pandemic circumstances, a dermatological assessment of the skin condition was conducted which provided objective data on the presence of hand eczema and type of skin lesions. Differences in baseline characteristics of the participants in IG and CG were small or negligible.
Since drop-out rates in studies with similar cohorts of participants often are high, 14 28 In previous studies on HCWs, the point prevalence is considerably higher with around 20% 2,29 ; this difference may be attributed to the disparity between self-reported and clinical examination-based studies. This assumption is also supported by the fact that in our study self-reported data on hand eczema did merely correlate in a moderate way with the dermatologically assessed data, as was also shown in former studies. 30 It should be noted that within the study cohort, the prevalence of clinical signs associated with HE was high at T0, whereby scaling as clinical sign of dry skin was most commonly observed. This coincides with current data by Lan et al. 11 from China, who report on xerosis cutis being a frequent adverse skin condition in HCWs during the COVID-19 pandemic.
In terms of risk factors, atopic skin diathesis increased odds of developing HE in the control group in the present study. This was to be expected as the relation of an atopic skin diathesis and the development of HE is well described. 31 This finding, however, stresses the need for preventative measures, especially in the group of people affected by an atopic skin diathesis. It is important to note that there were only 18 HE cases in the CG at T2. In a sample with a larger number of HE cases, probably further relevant factors could have been identified. This should be monitored in future studies.
Based on the OHSI total score and the OHSI values for scaling and erythema, there was a statistically significant difference between IG and CG at T2 (which was not the case at T0; values at T2 were better-i.e., lower-in the IG) as well as between IG and CG with respect to improvement over the course of the observation period.
The circumstance that there is only an improvement in the IG and even an aggravation of the skin condition in the CG indicates that the intervention was effective in improving existing skin changes on the hands. The lack of statistically significant changes for papules and fissures can be explained by the fact that values for these signs were already very low at T0. The statistically significant but descriptively small differences for vesicles and infiltration might be explained by the large sample and are probably not of a practical relevance. The overall low OHSI scores at T0 suggest that primarily participants with mild or no skin changes participated.
In the present study, daily frequency of emollient use at work and at home was considered an indicator for skin care behaviour. For both, statistically significant differences between IG and CG at T2 as well as between IG and CG with respect to the improvement over the health education measures should be repeated regularly. 16,32 The products used in this study were kindly provided in the sense of proof-of-concept by the manufacturer free of charge over the whole study period in unlimited amounts. The hand washing oil was scented.
Generally, from a dermatological and allergological point of view, unscented products are recommendable, even though the scent of a product might have a positive effect on user acceptance. 33 As the hand washing oil is a rinse-off product, it was considered tolerable to have fragrances, also keeping in mind the varying sensitizing potential of different fragrances. 34 The hand cream contained oat flour, which can be a skin sensitizer. However, reports on this allergen are rare 35 and none of the participants had to be excluded due to an allergy to this substance; the same applies for fragrances. Also, we did not observe any adverse skin reactions to the products provided.
The implemented online health education based on an asynchronous store-and-forward technology combined with information sheets (printouts) enabled a flexible and time-efficient access to the educational contents, as it has already been done in a slightly different manner, for example, by Madan et al. 36  option to ensure that the content is consumed as desired. As a further development, it would be imaginable to monitor participation and contact participants who did not use the offered measure (closed system in which activity can be monitored). This way it would be possible to monitor missing utilization at every measurement occasion, assess reasons for non-utilization and improve the concept accordingly. For complex interventions, intervention effects cannot be ascribed to specific parts of the intervention but only to the concept as a whole. In future studies, the study design could be modified in terms of adding two more intervention groups (one group only getting online-based health education and one group only getting the products). This would enable examining whether a specific component of the intervention is particularly effective or whether the two-part intervention concept only works as a whole.
Moreover, hands-on teaching with practical exercises might be more effective in improving behaviour. Prospectively, the described intervention could be used as is or could-when the pandemic conditions again facilitate face-to-face methods of health education-partly be adapted and integrated into these educational concepts also in order to increase participation. Particularly, healthcare trainees may benefit from such interventions in order to prevent onset of HE at an early career stage.

| CONCLUSION
The results of this study highlight that realization of adequate infection control concomitant with appropriate hygiene measures should go hand in hand with the implementation of adapting skin care regimes in order to efficiently promote skin health in HCWs. This may prevent individual suffering and impaired quality of life caused by HE as well as minimize costs of illness for social insurance systems and employers. Additionally, the manpower of HCWs-who are urgently needed-is preserved, which seems especially relevant in light of the ongoing COVID-19 pandemic. [38][39][40][41] The present study contributes to addressing the need of detailed, comprehensive and purposeful interventional studies with the aim of preventing occupational dermatoses in HCWs, which has frequently been demanded by experts. 13,[42][43][44] It is conceivable that the intervention might also be effective in various other skin hazardous professions, even beyond the human service sector.